Separation of minerals by flotation



?atented June 21, 1932 L. PERKINS, OF EAST AURORA, NEW YO FREDERICK G. MOSES, OF NEW YORK, RAY

MOND W. HESS, OF BUFFALO, AND ROBERT BK,

ASSIGNORS TO THE BARRETT COMPANY,

OF NEW YORK, N. Y., A CORPORATION OF NEW JERSEY SEPARATION OF MINERALS BY FLOTATION Ito Drawing.

where R denotes an alkyl group and X signifies a. hydroxyl group or an amino group which may contain substituent s. The thicacyl compounds of particular interest are those which correspond with the following formula.

RCS NHR where R denotes an alkyl group and R signifies a hydrogen atom or a hydrocarbon radical and more especially an aryl radical of the benzene series. Among the thioacyl compounds which may be mentioned as giving improved results in the process of the present invention are included the following: thioacetic acid, CH,.CS.Oll-I, thioacetamide, CH CSNPL, thioacetanilide,

CH CSNHC H etc. The flotation agents of the present invention may be prepared by methods described in the chemical literature.

In carrying out the flotation process, the flotation agent comprising one or more of the above mentioned thioacyl compounds may be incorporated with the ore or mineral pulp in any suitable manner or at any suitable time which will insure a satisfactory flotation operation. For example, it may be introduced in the free state or as a salt into the mill in which the ore is being ground, or it may be dissolved, suspended, or dispersed in any suitable solvent or dispersing agent as, for example, in one or more of the usual flotation oils or oil mixtures, or in any suitable organic other factors.

Application filed Kay 20, 1927. Serial No. 193,060.

to advantage in conjunction with other flotation agents. They may be used in the pure or purified state; and, in general, they may also be employed in the crude or impure state.

The process of the present invention can be carried out in any suitable apparatus, for example, those of the pneumatic type such as the Oallow cell, or those where the air is incorporated with the mixture by agitation such as the J anney apparatus or the like.

It is of advantage in some cases, as with certain copper ores, to subject the ore pulp to the action of an amount of alkali suflicient to give it an alkaline reaction before subjecting it to flotation with the flotation agents of the present invention. The alkali may be caustic alkali such as caustic soda, or an alkaline salt such as soda ash. or it may be calcium oxide or hydrate. In the diflerential separation of various minerals. such as zinc blende from associated minerals, the'presence of an alkali metal cyanide, or of copper sulfate or other salts is sometimes advantageous.

The amount of flotation agent required to be used in the flotation process will vary, it depending partly on the character and composition of the ore, partly on the particular thioacyl compound employed, and partly on Ordinarily, one-sixth to one half pound of the flotation agent per ton of dry ore'will be suflicient, but larger or smaller amounts than this may be used.

The invention will be "further illustrated as by the following specific examples. but it will be understood that the invention is not limited thereto. The parts are by weight.

' Example 1.500 parts of a copper sulfide ore (of the Miami Copper Company) assay' ing 1.25 percent copper was ground in a ball mill with 300 parts of water and 0.75 parts of hydrated lime (equivalent to 3 pounds per ton of ore) until practically all of it was sufficiently fine to pass through a 40 mesh screen. The ground pulp was diluted with suflicient water to give a pulp containing about 16 per- .cent solids and subjected to flotation in a 18.37 percent copper was obtained which is a recovery in the concentrate of 73.5 percent of the copper. The tailings assayed 0.35 percent copper. It willbe noted that the equivalent of about 19.9 tons of ore was required to give one ton of concentrate.

Example 2.500 parts of copper su lfide ore (of the Miami Copper Company) assaying 1.20 percent copper was ground in a ball mill with 310 parts of water and 0.75 parts of hydrated lime (equivalent to 3 pounds per ton of ore) until practically all of it was sufficiently fine to pass through a 40 mesh screen. The ground pulp was diluted with suflicient water to give a pulp containing about 16 percent solids and subjected to flotation in a J anney mechanical apparatus with the addition of 0.0625 parts of thioacetanilide (equivalent to one-fourth pound per ton 0t ore) previously dissolved in an equivalent amount of normal caustic soda solutlon. The mixture was agitated for 30 minutes during which time about 0.08 parts of pine oil were introduced. 23.0.parts of concentrate assaying 20.0 percent copper was obtained which is a recovery in the concentrate of 77.5 percent of the copper. The tailings assayed 0.28

percent copper. It will be noted that the equivalent of about 21.6 tons of ore was required to give one ton of concentrate.

E trample 3-500 parts of a copper sulfide ore (of the Miami Copper Company) assaying 1.21 percent copper was ground in a ball mill with 290 parts of water and 0.75 parts of hydrated lime (equivalent to 3 pounds per ton of ore) until practically all of it was sufiieiently fine to pass through a 40 mesh screen. The ground pulp was diluted with suflicient water to give a pulp containing about 16 percent solids and subjected to flotation in a J anney mechanical apparatus with the additionof 0.0625 parts of thioacetamide (equivalent to one-fourth pound per ton of ore) previously dissolved in an equivalent amount of normal caustic soda solution. The mixture wasagitated for 30 minutes during which time about 0.06 parts of pine oil were introduced. 27.8 parts of concentrate assaying 16.7 percent copper was obtained which is a recovery in the concentrate of 76.0 per cent of the copper. The tailings assayed 0.31 percent copper. It will be noted that the equivalent of about 18.2 tons of ore was required to give one ton of concentrate.

It will thus be noted that the present invention contemplates the'utilization as flotation agents in the separation of minerals and the concentration of ores of thioacyl compounds. corresponding with the formula,

where R denotes an alkyl group and X signifies a hydroxyl group or an amino group which may contain constituents; that said flotation agents may be incorporated in or with the ore or mineral pulp at any suitable time and in any suitable manner; that they may be used in the free state or as salts or in' the examples and that other agents, particularly other flotation agents of the class specified, can be similarly used.

We claim:

- 1. In effecting the separation of minerals, theprocess which comprises incorporating with the mineral pulp a thioacyl compound corresponding with the probable formula R-CS-NHR' where R denotes an alkyl group and R signifies a hydrogen atom or a hydrocarbon radical, and subjecting the resulting mixture to a froth flotation operation.

3. In eflecting the separation of minerals, the process which comprises incorporating with the mineral pulp a thioacyl compound corresponding with the probable formula R-CS-NHR where R denotes an alkyl group and R signifies an aryl radical, and sub ect1ng the resulting mixture to a froth flotation operation.

4. In effecting the separation of minerals, the process which comprises incorporating with the mineral pulp a thioacyl compoun corresponding with the probable formula RCS.NHR y where R denotes an alkyl group and R slgnifies a hydrocarbon radical of the hen- -zene series, and subjecting the resulting mixture to a froth flotation operation.

5. In effecting the separation of minerals, the process which comprises incorporating with themineral pulp a thioacyl compound corresponding with the probable formula where R denotes an alkyl group. and subjecting the resulting mixture to a froth flotation operation.

8. In effecting the separation of minerals, the process which comprises incorporating thioac'etamide with a mineral pulp and subjecting the resulting mixture to a froth flotation operation.

9. In effecting the separation of minerals, the process which comprises incorporating with a mineral pulp a thioacyl compound corresponding with the probable formula where R denotes an alkyl group, and subjecting the resulting mixture to a froth flotation operation.

10. In effecting the separation of minerals, the process which comprises incorporating thioacetic acid with a mineral pulp and subjecting the resulting mixture to afroth flotation operation.

In testimony whereof we atfix our signatures.

FREDERICK G. MOSES. RAYMOND W. HESS. ROBERT L. PERKINS. 

